Error occurred during Offline Synchronization

Hi All,

When I click on 'Go Offline' from inside my Outlook program I receive an error message.

Here is the Windows error.

An error occurred during Offline Synchronization.  Try going offline again, or restart Microsoft Outlook. Exception happened Cannot insert duplicate key row in object 'MetadataSchema.Attribute' with unique index 'ndx_Attribute_EntityId_ColumnNumber'. The duplicate key value is (e1bd1119-6e9d-45a4-bc15-12051e65a0bd, 385).
The statement has been terminated..
 Stack Trace Info:
 
Server stack trace:
   at System.ServiceModel.Channels.ServiceChannel.ThrowIfFaultUnderstood(Message reply, MessageFault fault, String action, MessageVersion version, FaultConverter faultConverter)
   at System.ServiceModel.Channels.ServiceChannel.HandleReply(ProxyOperationRuntime operation, ProxyRpc& rpc)
   at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs, TimeSpan timeout)
   at System.ServiceModel.Channels.ServiceChannelProxy.InvokeService(IMethodCallMessage methodCall, ProxyOperationRuntime operation)
   at System.ServiceModel.Channels.ServiceChannelProxy.Invoke(IMessage message)

Exception rethrown at [0]:
   at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)
   at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type)
   at Microsoft.Crm.Application.Outlook.OfflineSync.IRemoteSyncData.Sync(TransferDataMethod provider, String metadataForMetadataVersion)
   at Microsoft.Crm.Application.SMWrappers.OfflineSync.<SyncThreadMethod>b__0()
   at Microsoft.ExceptionHelper.ExceptionFilter.TryFilterAllCatch(Action body, Action`1 filter) .

If anybody can shed some light on the what is happening here it will be greatly appreciated.

Kind Regards,

Davo